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Re: [PATCH v3 2/2] lockable: replaced locks with lock guard macros where
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [PATCH v3 2/2] lockable: replaced locks with lock guard macros where appropriate |
Date: |
Fri, 20 Mar 2020 12:33:48 +0000 |
User-agent: |
Mutt/1.13.3 (2020-01-12) |
* address@hidden (address@hidden) wrote:
> From: Daniel Brodsky <address@hidden>
>
> - ran regexp "qemu_mutex_lock\(.*\).*\n.*if" to find targets
> - replaced result with QEMU_LOCK_GUARD if all unlocks at function end
> - replaced result with WITH_QEMU_LOCK_GUARD if unlock not at end
>
> Signed-off-by: Daniel Brodsky <address@hidden>
> ---
> block/iscsi.c | 11 +++-------
> block/nfs.c | 51 ++++++++++++++++++++-----------------------
> cpus-common.c | 13 +++++------
> hw/display/qxl.c | 43 +++++++++++++++++-------------------
> hw/vfio/platform.c | 5 ++---
> migration/migration.c | 3 +--
> migration/multifd.c | 8 +++----
> migration/ram.c | 3 +--
> monitor/misc.c | 4 +---
> ui/spice-display.c | 14 ++++++------
> util/log.c | 4 ++--
> util/qemu-timer.c | 17 +++++++--------
> util/rcu.c | 8 +++----
> util/thread-pool.c | 3 +--
> util/vfio-helpers.c | 4 ++--
> 15 files changed, 84 insertions(+), 107 deletions(-)
>
<snip>
> diff --git a/migration/migration.c b/migration/migration.c
> index c1d88ace7f..2f0bd6d8b4 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1652,11 +1652,10 @@ static void migrate_fd_cleanup_bh(void *opaque)
>
> void migrate_set_error(MigrationState *s, const Error *error)
> {
> - qemu_mutex_lock(&s->error_mutex);
> + QEMU_LOCK_GUARD(&s->error_mutex);
> if (!s->error) {
> s->error = error_copy(error);
> }
> - qemu_mutex_unlock(&s->error_mutex);
> }
There are some other places in migration.c that would really benefit;
for example, migrate_send_rp_message, if you use a LOCK_QUARD
there, then you can remove the 'int ret', and the goto error.
In postcopy_pause, the locks on qemu_file_lock would work well using the
WITH_QEMU_LOCK_GUARD.
> void migrate_fd_error(MigrationState *s, const Error *error)
> diff --git a/migration/multifd.c b/migration/multifd.c
> index cb6a4a3ab8..9123c111a3 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -894,11 +894,11 @@ void multifd_recv_sync_main(void)
> for (i = 0; i < migrate_multifd_channels(); i++) {
> MultiFDRecvParams *p = &multifd_recv_state->params[i];
>
> - qemu_mutex_lock(&p->mutex);
> - if (multifd_recv_state->packet_num < p->packet_num) {
> - multifd_recv_state->packet_num = p->packet_num;
> + WITH_QEMU_LOCK_GUARD(&p->mutex) {
> + if (multifd_recv_state->packet_num < p->packet_num) {
> + multifd_recv_state->packet_num = p->packet_num;
> + }
> }
> - qemu_mutex_unlock(&p->mutex);
> trace_multifd_recv_sync_main_signal(p->id);
> qemu_sem_post(&p->sem_sync);
> }
> diff --git a/migration/ram.c b/migration/ram.c
> index c12cfdbe26..87a670cfbf 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -1368,7 +1368,7 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t
> *offset)
> return NULL;
> }
>
> - qemu_mutex_lock(&rs->src_page_req_mutex);
> + QEMU_LOCK_GUARD(&rs->src_page_req_mutex);
> if (!QSIMPLEQ_EMPTY(&rs->src_page_requests)) {
> struct RAMSrcPageRequest *entry =
> QSIMPLEQ_FIRST(&rs->src_page_requests);
> @@ -1385,7 +1385,6 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t
> *offset)
> migration_consume_urgent_request();
> }
> }
> - qemu_mutex_unlock(&rs->src_page_req_mutex);
>
> return block;
> }
Is there a reason you didn't do the matching pair at the bottom of
ram_save_queue_pages ?
Dave
> diff --git a/monitor/misc.c b/monitor/misc.c
> index 6c45fa490f..9723b466cd 100644
> --- a/monitor/misc.c
> +++ b/monitor/misc.c
> @@ -1473,7 +1473,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool
> has_fdset_id, int64_t fdset_id,
> MonFdsetFd *mon_fdset_fd;
> AddfdInfo *fdinfo;
>
> - qemu_mutex_lock(&mon_fdsets_lock);
> + QEMU_LOCK_GUARD(&mon_fdsets_lock);
> if (has_fdset_id) {
> QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
> /* Break if match found or match impossible due to ordering by
> ID */
> @@ -1494,7 +1494,6 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool
> has_fdset_id, int64_t fdset_id,
> if (fdset_id < 0) {
> error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id",
> "a non-negative value");
> - qemu_mutex_unlock(&mon_fdsets_lock);
> return NULL;
> }
> /* Use specified fdset ID */
> @@ -1545,7 +1544,6 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool
> has_fdset_id, int64_t fdset_id,
> fdinfo->fdset_id = mon_fdset->id;
> fdinfo->fd = mon_fdset_fd->fd;
>
> - qemu_mutex_unlock(&mon_fdsets_lock);
> return fdinfo;
> }
>
> diff --git a/ui/spice-display.c b/ui/spice-display.c
> index 6babe24909..19632fdf6c 100644
> --- a/ui/spice-display.c
> +++ b/ui/spice-display.c
> @@ -18,6 +18,7 @@
> #include "qemu/osdep.h"
> #include "ui/qemu-spice.h"
> #include "qemu/timer.h"
> +#include "qemu/lockable.h"
> #include "qemu/main-loop.h"
> #include "qemu/option.h"
> #include "qemu/queue.h"
> @@ -483,12 +484,12 @@ void qemu_spice_display_refresh(SimpleSpiceDisplay *ssd)
> {
> graphic_hw_update(ssd->dcl.con);
>
> - qemu_mutex_lock(&ssd->lock);
> - if (QTAILQ_EMPTY(&ssd->updates) && ssd->ds) {
> - qemu_spice_create_update(ssd);
> - ssd->notify++;
> + WITH_QEMU_LOCK_GUARD(&ssd->lock) {
> + if (QTAILQ_EMPTY(&ssd->updates) && ssd->ds) {
> + qemu_spice_create_update(ssd);
> + ssd->notify++;
> + }
> }
> - qemu_mutex_unlock(&ssd->lock);
>
> trace_qemu_spice_display_refresh(ssd->qxl.id, ssd->notify);
> if (ssd->notify) {
> @@ -580,7 +581,7 @@ static int interface_get_cursor_command(QXLInstance *sin,
> QXLCommandExt *ext)
> SimpleSpiceDisplay *ssd = container_of(sin, SimpleSpiceDisplay, qxl);
> int ret;
>
> - qemu_mutex_lock(&ssd->lock);
> + QEMU_LOCK_GUARD(&ssd->lock);
> if (ssd->ptr_define) {
> *ext = ssd->ptr_define->ext;
> ssd->ptr_define = NULL;
> @@ -592,7 +593,6 @@ static int interface_get_cursor_command(QXLInstance *sin,
> QXLCommandExt *ext)
> } else {
> ret = false;
> }
> - qemu_mutex_unlock(&ssd->lock);
> return ret;
> }
>
> diff --git a/util/log.c b/util/log.c
> index 2da6cb31dc..bdb3d712e8 100644
> --- a/util/log.c
> +++ b/util/log.c
> @@ -25,6 +25,7 @@
> #include "qemu/cutils.h"
> #include "trace/control.h"
> #include "qemu/thread.h"
> +#include "qemu/lockable.h"
>
> static char *logfilename;
> static QemuMutex qemu_logfile_mutex;
> @@ -94,7 +95,7 @@ void qemu_set_log(int log_flags)
> if (qemu_loglevel && (!is_daemonized() || logfilename)) {
> need_to_open_file = true;
> }
> - qemu_mutex_lock(&qemu_logfile_mutex);
> + QEMU_LOCK_GUARD(&qemu_logfile_mutex);
> if (qemu_logfile && !need_to_open_file) {
> logfile = qemu_logfile;
> atomic_rcu_set(&qemu_logfile, NULL);
> @@ -136,7 +137,6 @@ void qemu_set_log(int log_flags)
> }
> atomic_rcu_set(&qemu_logfile, logfile);
> }
> - qemu_mutex_unlock(&qemu_logfile_mutex);
> }
>
> void qemu_log_needs_buffers(void)
> diff --git a/util/qemu-timer.c b/util/qemu-timer.c
> index d548d3c1ad..b6575a2cd5 100644
> --- a/util/qemu-timer.c
> +++ b/util/qemu-timer.c
> @@ -459,17 +459,16 @@ void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t
> expire_time)
> QEMUTimerList *timer_list = ts->timer_list;
> bool rearm;
>
> - qemu_mutex_lock(&timer_list->active_timers_lock);
> - if (ts->expire_time == -1 || ts->expire_time > expire_time) {
> - if (ts->expire_time != -1) {
> - timer_del_locked(timer_list, ts);
> + WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
> + if (ts->expire_time == -1 || ts->expire_time > expire_time) {
> + if (ts->expire_time != -1) {
> + timer_del_locked(timer_list, ts);
> + }
> + rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
> + } else {
> + rearm = false;
> }
> - rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
> - } else {
> - rearm = false;
> }
> - qemu_mutex_unlock(&timer_list->active_timers_lock);
> -
> if (rearm) {
> timerlist_rearm(timer_list);
> }
> diff --git a/util/rcu.c b/util/rcu.c
> index 177a675619..60a37f72c3 100644
> --- a/util/rcu.c
> +++ b/util/rcu.c
> @@ -31,6 +31,7 @@
> #include "qemu/atomic.h"
> #include "qemu/thread.h"
> #include "qemu/main-loop.h"
> +#include "qemu/lockable.h"
> #if defined(CONFIG_MALLOC_TRIM)
> #include <malloc.h>
> #endif
> @@ -141,14 +142,14 @@ static void wait_for_readers(void)
>
> void synchronize_rcu(void)
> {
> - qemu_mutex_lock(&rcu_sync_lock);
> + QEMU_LOCK_GUARD(&rcu_sync_lock);
>
> /* Write RCU-protected pointers before reading p_rcu_reader->ctr.
> * Pairs with smp_mb_placeholder() in rcu_read_lock().
> */
> smp_mb_global();
>
> - qemu_mutex_lock(&rcu_registry_lock);
> + QEMU_LOCK_GUARD(&rcu_registry_lock);
> if (!QLIST_EMPTY(®istry)) {
> /* In either case, the atomic_mb_set below blocks stores that free
> * old RCU-protected pointers.
> @@ -169,9 +170,6 @@ void synchronize_rcu(void)
>
> wait_for_readers();
> }
> -
> - qemu_mutex_unlock(&rcu_registry_lock);
> - qemu_mutex_unlock(&rcu_sync_lock);
> }
>
>
> diff --git a/util/thread-pool.c b/util/thread-pool.c
> index 4ed9b89ab2..d763cea505 100644
> --- a/util/thread-pool.c
> +++ b/util/thread-pool.c
> @@ -210,7 +210,7 @@ static void thread_pool_cancel(BlockAIOCB *acb)
>
> trace_thread_pool_cancel(elem, elem->common.opaque);
>
> - qemu_mutex_lock(&pool->lock);
> + QEMU_LOCK_GUARD(&pool->lock);
> if (elem->state == THREAD_QUEUED &&
> /* No thread has yet started working on elem. we can try to "steal"
> * the item from the worker if we can get a signal from the
> @@ -225,7 +225,6 @@ static void thread_pool_cancel(BlockAIOCB *acb)
> elem->ret = -ECANCELED;
> }
>
> - qemu_mutex_unlock(&pool->lock);
> }
>
> static AioContext *thread_pool_get_aio_context(BlockAIOCB *acb)
> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
> index ddd9a96e76..b310b23003 100644
> --- a/util/vfio-helpers.c
> +++ b/util/vfio-helpers.c
> @@ -21,6 +21,7 @@
> #include "standard-headers/linux/pci_regs.h"
> #include "qemu/event_notifier.h"
> #include "qemu/vfio-helpers.h"
> +#include "qemu/lockable.h"
> #include "trace.h"
>
> #define QEMU_VFIO_DEBUG 0
> @@ -667,14 +668,13 @@ int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s)
> .size = QEMU_VFIO_IOVA_MAX - s->high_water_mark,
> };
> trace_qemu_vfio_dma_reset_temporary(s);
> - qemu_mutex_lock(&s->lock);
> + QEMU_LOCK_GUARD(&s->lock);
> if (ioctl(s->container, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
> error_report("VFIO_UNMAP_DMA failed: %s", strerror(errno));
> qemu_mutex_unlock(&s->lock);
> return -errno;
> }
> s->high_water_mark = QEMU_VFIO_IOVA_MAX;
> - qemu_mutex_unlock(&s->lock);
> return 0;
> }
>
> --
> 2.25.1
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
Re: [PATCH v3 0/2] Replaced locks with lock guard macros, no-reply, 2020/03/20